Electric utility companies need to provide and maintain generating facilities and distribution networks which are ample by a safe margin to meet the demand for electric power during periods of peak or maximum demand. Such requirements are needed to maintain their competitive position as suppliers of energy as well as meeting certain governmental regulations. The level of electrical power consumed during other than these peak periods is considerably less than the peak demand; however, to meet the peak demand a considerable investment in generating facilities and distribution networks is needed and yet during a good portion of the time such generating facilities may be idle. To eliminate the investment of several hundred thousand dollars for extra capacity to meet these peak demands, various systems have been used in the past to reduce the demand for electrical energy during the peak periods.
For example, in the control of electric water heaters, timing mechanisms, and even elaborate signaling systems for controlling electric water heaters over the power line by superimposed control signals, have been devised for disconnecting electrical loads during a peak period to reduce the peak demand. Another type of system, such as that shown in the Robert L. Coe U.S. Pat. No. 3,261,992, patented July 19, 1966, is used for selectively disconnecting an electrical refrigeration apparatus when the outdoor temperature exceeds some predetermined value to decrease the peak electrical demand. Another device is shown in a co-pending application of Lorne W. Nelson, Ser. No. 705,214, filed July 14, 1976, entitled REFRIGERATION LOAD SHEDDING CONTROL DEVICE.
The present invention is an improvement to the device of the Lorne W. Nelson application wherein a device for use with the electrical load apparatus has an outdoor temperature responsive switch means connected in the control circuit and the temperature responsive portion of the outdoor temperature responsive switch means is artifically heated by a heater which is energized each time the electrical load apparatus is energized for operation.